1. Field of the Invention
This invention relates to a direct injection-locked frequency divider circuit with inductive-coupling feedback architecture which is designed for integration to a high-frequency circuit system with a high operating frequency such as 24 GHz (gigahertz), for providing a frequency-dividing function.
2. Description of Related Art
With the advent of wireless digital communication technologies, such as wireless networking, mobile phones, GPS (Global Positioning System), and digital TV, the design and manufacture of high-speed digital circuits that operate with signals within the gigahertz range is in high demand in the electronics industry. Nowadays, the operating frequency of high-speed digital circuitry has advanced to the level of 24 GHz.
In the design of high-speed digital circuitry, frequency dividers are an important component that can provide a frequency-dividing function to generate an output signal whose frequency is a divide-by-N fraction of the input signal frequency. Presently, since most high-speed digital circuits are utilized on portable electronic devices, the circuit design typically requires low power consumption and small layout size. Moreover, in order to achieve high performance, the design of high-speed digital circuitry also demands low noise and wide frequency locking range.